Tools · Time
Time Studio
Ten tools that usually mean ten tabs: a countdown timer, a stopwatch, an alarm, a countdown to a date, date difference and add-or-subtract, business days with the US federal holidays named, ISO week numbers, a timezone converter, a meeting planner and Unix time. Every clock is read from your system clock and every conversion from the timezone data your browser already ships — nothing is uploaded.
10:00
The end time is computed from the clock, so switching tabs never makes the countdown drift — but browsers throttle background tabs, so the sound can arrive a little late. The tab title shows the remaining time.
Every timer, conversion and date here runs in this browser tab and nowhere else — nothing is uploaded, logged or stored.
Questions people actually ask
- Which week number is it right now?
- This page uses ISO 8601, the standard behind almost every European calendar and every “week 37” in a project plan: weeks start on Monday, and a week belongs to whichever year its Thursday falls in. That is why 1 January is sometimes week 52 or 53 of the year before, and why 29 December can already be week 1 of the year after. An ISO year has 53 weeks when it starts on a Thursday, or on a Wednesday in a leap year — otherwise 52. The US convention (weeks start Sunday, week 1 is the one containing 1 January) produces different numbers, so if a payroll or retail calendar disagrees with this page, that is usually why.
- What happens when a US federal holiday falls on a weekend?
- It moves, and the business-day count moves with it. Under 5 U.S.C. § 6103 a holiday landing on a Saturday is observed the Friday before, and one landing on a Sunday is observed the Monday after. This tool always reports the observed date and appends “(observed)” to the name when it has shifted. One consequence catches people out: when 1 January falls on a Saturday, that holiday is observed on 31 December — inside the previous year’s count.
- Which holidays are counted, and which are not?
- The eleven federal holidays: New Year’s Day, Martin Luther King Jr. Day (third Monday in January), Washington’s Birthday (third Monday in February), Memorial Day (last Monday in May), Juneteenth (from 2021, when it was created), Independence Day, Labor Day (first Monday in September), Columbus Day (second Monday in October), Veterans Day, Thanksgiving (fourth Thursday in November) and Christmas Day. State holidays, non-US bank holidays and your own company shutdown days are not included — the tool prints the holidays it found by name so you can check them against your own calendar before promising a date. Business days are counted inclusive of both the start and the end date, which is the convention deadlines are usually written in.
- Does the timezone converter handle daylight saving?
- Yes, and it handles it for the date you asked about rather than for today. Every conversion goes through the IANA time zone database the browser already ships, so a call in London on 3 November converts at GMT even if you are planning it in July, when the same city is on BST. Two edge cases are worth knowing. On a spring-forward night an hour never happens: ask for 2:30 a.m. in a zone that jumps 2:00 to 3:00 and you get 3:30, the same choice most calendar apps make. On a fall-back night an hour happens twice, and the converter settles on one of the two instants rather than asking which you meant.
- Will the timer keep running if I switch tabs?
- The reading stays right; the beep can be late. Every clock here is computed from the system clock each time it redraws — end time minus now — rather than by adding up ticks, so a throttled background tab cannot make the countdown drift the way tick-counting timers do. What browsers throttle is how often a hidden page gets to run at all: once a second, sometimes less. A timer that hits zero while hidden can therefore sound a few seconds after the moment it shows. The remaining time is written into the tab title so you can read it without switching back.
- Does the alarm ring if I close the tab?
- No — and no web page can honestly promise otherwise. The sound is generated by a WebAudio oscillator inside this tab, so closing the tab, quitting the browser or letting the machine sleep all stop it. Arming the alarm also has to be a click, because browsers only unlock audio after a real gesture; that is a browser rule rather than a choice made here. For anything you must not miss, set your phone. Use this one for the pasta.
- Is that timestamp in seconds or milliseconds?
- The Unix panel decides by size: a value under 1e12 is read as seconds, anything larger as milliseconds. The two ranges never overlap in practice — 1e12 seconds is the year 33658, while 1e12 milliseconds was September 2001 — so a ten-digit number is Unix time as most APIs and databases send it, and a thirteen-digit number is JavaScript’s Date.now(). The panel says which unit it used and shows the conversion both ways, so a misread is visible rather than silent.
- Do the dates and times I type here go anywhere?
- No. This page makes no server call at all: the date arithmetic, the holiday calendar and every timezone conversion run in this tab, against the zone data your browser already carries. That matters more than it sounds, because what people put into a date calculator is often a due date, a court deadline, a medical appointment or an interview they have not told anyone about yet. Close the tab and none of it exists anywhere.
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